Bluefin Trevally

Interesting Info

• The Bluefin Trevally (Caranx melampygus) is one of the most striking predators on the reef — its fins glow with electric blue, and its sleek silver body glitters with a faint golden tint and scattered blue spots.
• Their body is deep and streamlined, built for powerful acceleration when chasing prey.
• Juveniles start life in shallow lagoons, estuaries, and sandy bays, where they find shelter and food. As they grow, they move offshore to deeper reef slopes, outer atolls, and ocean drop-offs down to about 190 m (620 ft).
• They are widespread throughout the tropical Indo-Pacific — from the Red Sea and east Africa across to Japan, Hawaii, French Polynesia, and northern Australia.
• Bluefin Trevallies are agile hunters that feed mainly on small fish, squid, and crustaceans. They sometimes follow large predators like sharks or rays to ambush fleeing prey — a clever hunting strategy seen on coral reefs around the world.
• They reach sexual maturity at about 30–40 cm (12–16 in) and around two years of age. Spawning usually occurs in pairs or large groups, often during the warmer months and lunar peaks, with females releasing millions of eggs each season.
• Larvae and juveniles drift with ocean currents before settling onto coastal reefs. Growth is fast in the early years but slows as they reach adulthood.
• They can live for 12–15 years, although some studies suggest individuals in deep, offshore habitats might live even longer.
• Bluefin Trevallies are known for their intelligence and coordination — sometimes hunting cooperatively or using coral heads and reef ledges to corner prey.
• Their striking colours can change depending on mood or surroundings. During feeding or spawning, the fins glow a brighter neon blue and the body may darken dramatically.